U-Bolt bending machine

ABSTRACT

A bending machine for bending elongate metal stock into curved configurations. Two adjustably fixed spaced dies receive the stock thereagainst while a movable die moves between the fixed dies causing the metal to be bent into a curvature of up to 180*.

United States Patent Whitehead 5] Nov. 11, 1975 [5 U-BOLT BENDINGMACHINE 2.382.266 8/1945 Simonsen N 727389 x [76] Inventor: WillardWhitehead, 212 E. Indiana,

79701 Prl'lmlr E,\'amz'rzerMilton S. Mehr 22 pu 0 17 97 Attorney, Agent.or FirmMarcus L. Bates [2t] Appl. No.: 515,501

[57} ABSTRACT [52] US. Cl 72/213; 72/389 [5 1] Int. (II. .4 B21D 7/03 Adi hi for bending elongate metal stock new of Search 72/211 into curvedconfigurations. Two adjustably fixed 72/381 456 spaced dies receive thestock thereagainst while a movable die moves between the fixed diescausing the [56] References cued metal to be bent into a curvature of upto [80".

UNITED STATES PATENTS 2277.204 3/1942 Byler 72/213 10 Claims, 11 DrawingFigures US. Patent Nov.11, 1975 Sheet10f4 3,918,286

US. Patent Nov.11, 1975 Sheet2of4 3,918,286

FIG.2

FIG. 3

U.S. Patent Nov. 11, 1975 Sheet4 0f4 3,918,286

FIG.

FIG.

U-BOLT BENDING MACHINE THE PRIOR ART The US. Pat. Nos. to Kroetch3,724,256; Denninger 3,610,019; Hutch 3,429,I57; and, Shaw .Ir.3,260,091 are examples of the known prior art.

BACKGROUND OF THE INVENTION Bending machines for fabricating Ubolts andthe like are known as examplified by the above referred to prior artpatents. It is often desirable for small machine shops and fabricationshops to be able to bend tubular stock into a radius of curvature up to180, as for example the making of a U-bolt. Such a desirable expedientavoids carrying a large and expensive inventory, but also enables themost optimum choice of material since the exact desired part can befabricated at once, thereby effecting a savings in both time and money.

It is desirable that such a machine be low in cost, simple to operate,and efficient in operation.

SUMMARY OF THE INVENTION A bending machine for bending elongated metalstock into a curve having a radius of curvature up to 180. Two pivotedarms carry fixed dies at the pivoted end thereof. with the dies beingadjustably disposed in spaced relation to one another. The arms aresupported from a table.

A movable die is mounted to a power member by means of a mandrel withthe mandrel being brought through a slot in the table so that the tablecan form the main support structure for all of the apparatus.

The movable die is forced to pass between the fixed dies, therebycausing any stock placed therebetween to be bent according to theconfiguration of the movable die and the extent of relative movementbetween the fixed and movable dies.

Accordingly, a primary object of this invention is the provision of abending machine for forcing elongated metal stock into a non-linearconfiguration;

Another object of the invention is to provide a bending machine for usein fabricating U-bolts from elon gated metal stock.

A further object of this invention is to provide a bending machine inwhich spaced fixed dies and a movable die cooperate together in a novelmanner to provide a U-bolt in an unexpected manner.

A still further object of this invention is to provide a bending machinewhich is simple to operate, low in initial cost, safe in operation, andefficient in design.

The above objects are attained in accordance with the present inventionby the provision ofa combination of elements which are fabricated in amanner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view ofapparatus made in ac cordance with the present invention;

FIG. 2 is a diagrammatical, part schematical representation of animportant principal of operation of the present invention;

FIG. 3 is a broken, part cross-sectional representation which sets forthsome of the details of the invention;

FIG. 4 is a longitudinal, part cross-sectional view which sets forthsome important details of the present invention, with some parts beingbroken away to more clearly illustrate what lies therebeyond;

FIG. 5 is a top plan view of apparatus disclosed in the foregoingfigures, with parts being broken away there- 5 from to discloseimportant aspects of the invention;

FIG. 6 is an end view of the apparatus disclosed in FIG. 5;

FIG. 7 is an enlarged detailed top view of part of the apparatusdisclosed in FIGS. 5 and 6;

FIG. 8 is an enlarged detail taken along line 8-8 of FIG. 7;

FIG. 9 is a bottom view looking along the arrows indicated by line 9-9of FIG. 8;

FIG. 10 is a side elevational view of another form of the invention;and,

FIG. 11 is a bottom view taken along line 11-11 of FIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED 20 EMBODIMENT Throughout thefigures of the drawing, wherever possible, like or similar numerals willrefer to like or similar elements thereof. In the figures of the drawingthere is disclosed a U-bolt bending machine 10 comprised of a reinforcedtable I2, a bending die 14 which moves relative to table 12, a rollerdie 16 spaced from a second roller die I7 with the dies being adjustablymounted in fixed relation respective to one another and to the table. Alongitudinally extending marginal portion of a rod having the marginalopposed ends thereof threaded and placed in the illustrated manner ofFIG. 2a so that opposed ends L1, L2 of the rod are bent toward oneanother as axis Cl and C2 move through one another.

As particularly seen in FIG. 2a, the roller dies 16 and 17 are disposedalong axes C1 with the threaded rod 18 having a marginal portion 19abuttingly engaged with an outer peripheral wall surface of the rollerdies. The rod also engages a flat leading edge portion of the centraldie 14.

In FIG. 2b axis Cl and C2 remain parallel and are forced to move towardone another thereby breaking the central marginal portion 19 of the rodinto the beginning of a radius of curvature seen illustrated at l9 inFIG. 2b and 119 in FIG. 2c.

As seen in FIG. 3, a mandrel 20 has a lower end portion 22 and anopposite upper end portion, the latter being provided with a verticalindex key 23 and the former being provided with a horizontal index key24. As seen in FIG. 7, a keyway 26 is cut into the movable die. Theouter peripheral surface 27 of the movable die ordinarilycircumferentially extends in a manner as indi cated by the dot-dashedarea 27. The leading edge of the die is provided with a verticallydisposed face 28 for initially engaging stock 19. Numeral 29 indicatesthe bending configuration of stock 19 in the absence of face 28 beingformed into the leading edge portion of the die,

On FIGS. 3, 4, and 8, it will be noted that power member 30 has acounterbore 32 formed therein complementary respective to members 20 and24 so that the mandrel is always arranged in indexed relationshiptherewith. Elongated slot 34 is formed longitudinally respective of thetable so that the mandrel can be moved within the slot andlongitudinally respective of the table.

Spaced arms in the form of adjustment plates 36 and 37 are spaced fromone another and pivotally secured to the table by means of pivot pins 38and 39 thereby enabling the positioning pins 40 and 41 to be movedtoward and away from one another when handle 42 rotates threaded member43. Member 43 threadedly en gages member 41 while the free marginal end42 is journaled to the pin 40. The rotatable fixed dies and thereforepositioned at the pivoted or swingable end of the arms. Handle 46cooperates with the illustrated arcuate slotted member 50 to provide afriction lock for member 36. Member 37 requires no friction lock forreasons which will be better appreciated later on in the disclosure.

The before mentioned power member 30 has opposed end portions 52 and 54.The member is slidably captured within L-shaped web members 56 and 58 sothat the power member can slide in low friction relationshiplongitudinally of the table an amount which enables full travel of themandrel along the length of slot 34.

As seen in FIGS. 3 and 4, a centrally located downwardly dependingmember 60, also called an ear, is rigidly affixed to the marginalforward end portion of member 30 and has rigidly affixed thereto a pin62 which has opposed ends arranged normally thereto. Cylinder 64 of ahydraulic unit has a piston 66 thereof journaled to the before mentionedpin, with the cylinder being journaled to pin 68. Biasing means in theform of opposed springs 70 and 71 are arranged on opposed sides of thehydraulic unit and have the depending ends thereof affixed to the pins62 and 68, thereby forming a return biasing means for the mandrel.Hence, the hydraulic unit reciprocates the power member forward whilethe biasing means reciprocates the power member in the oppositedirection,

Spaced vertical webs 72 form a mounting means for pin 68 and is rigidlyaffixed to the table and to the illustrated member 74. Member 75 isattached to the table and provides additional support for the apparatus.

Flow connection 76 is fluid connected to flow control valve 78 which inturn is connected to hydraulic pump 80 and to the reservoir 82. Valvecontroller 79 can be engaged by the foot to control the flow ofhydraulic fluid to and from the cylinder 64. Electric motor 81 iselectrically connected to the motor controller 84 while switch 86enables the entire apparatus to be de energized.

In operation, a suitable source of current is connected to thecontroller and the switch 86 turned on, thereby causing induction motor81 to actuate the pump 80, thereby providing a source of hydraulicpressure for the cylinder 64. When lever 79 is pushed in a downwarddirection by the foot, valve 78 causes fluid to flow into the cylinder64 thereby moving piston 66 which in turn moves pin 62, vertical webs60, power member 30, and the mandrel 20 longitudinally within its slot.

Prior to moving the mandrel in a forward direction, the proper sizemovable die is selected to provide a U- bolt having the proper desiredradius of curvature, The fixed roller dies are properly positionedrelative to one another so that the distance between the spaced boltengaging surfaces of the roller dies is exactly equal to the measureddistance between legs L1 and L2 of the finished U-bolt. A threaded bar19 is placed between the leading face 28 of the die and abuttinglyengages each of the rollers 16 and 17. The piston is reciprocated withinthe cylinder by engaging valve control rod 79 with the foot, therebycausing rollers l4, l6, 17 to move relative to one another asillustrated in FIG. 2a, 2b, and 20 Applicant has discovered that byremoving the area between 28 and 27' of the die 14, the bolt 19 will notcreep forward into the illustrated position 29 while it is being bentinto a U-shape in accordance with FIGS. 20, 2b, and 2c. The presence ofthe flat face or leading edge 28 causes the stock 19 to be bent into aperfect radius ofcurvature 119 as axis C] moves through axis C2. Thecurvature 19 or 119 is controlled by the amount of material removedbetween 27 and 28. Ordinarily, 15 percent to percent of the area of thedie, viewed in plan, is is removed in order to attain the desiredconflgura tion at 119.

The reason that the removal of the material at 28' results in a radiusof curvature 119 which coinsides with radius 27' of FIG. 7, for example,is because the bolt is engaged by the outer periphery 27 of the die asthe bending operation commences, and since the bolt is originallydeformed into an initial bend as a result of being forced between thethree dies, the marginal area of the bolt is caused to assume anundesirable sharp bend seen illustrated at 29 in FIG. 2b. By engaging alarger surface area of the bolt by a larger bearing area 28, a moreuniform and desirable radius of curvature 119 is achieved rather than anundesirable sharp bend 29.

Release of lever 79 causes the fluid flowing through pump 80 to bypassthe cylinder the flow to the reservoir 82, whereupon biasing means 70urges pins 62 and 68 toward one another, thereby returning the mandrelto its initial position respective to the slotted table, The apparatusis now in stand-by configuration awaiting fabrication of the nextU-bolt.

When it is deemed desirable to fabricate Ubolts of differentconfigurations, various different diameter dies can be substituted forthe one illustrated at numeral 14. For example, should a square U-boltbe deemed desirable, the apparatus disclosed in FIGS. 10 and I1 can beemployed in order to fabricate each bend of a square U-bolt. The amountof bend imparted into a piece of stock can be regulated by the distancetraveled by the moving die respective to the spaced fixed dies,

I claim:

1. In a bending machine for bending metal stock to produce U-bolts andthe like, a longitudinally extending table having a longitudinallyextending slot formed therein;

an elongated slidable power member underlying said slot, means slidablycapturing said power member to said table in a slidable and abuttingmanner to slidably engage abuting surfaces of said power member and saidtable;

a mandrel attached to said power member and having a free marginal endportion extending through said slot; a movable die affixed to themarginal free end portion of said mandrel;

spaced fixed dies equally spaced apart and from said movable die;

spaced arms pivotally secured to said table and having a swingable endto which there is attached said fixed die;

means for reciprocating said power member to move said mandrel alongsaid slot to cause said movable die to move between said fixed dies;

so that the central marginal length of a piece of metal stock placedagainst said fixed dies can be engaged by said movable die and bent intoa curved configuration.

2. The machine of claim 1 wherein said pivoted end of said spaced armsare adjustably secured to one an other by a tie rod;

means for adjusting the effective length of said tie rod, therebyenabling selection of the distance between said fixed dies.

3. The machine of claim 2 wherein said fixed dies include meansrotatably securing them in fixed relationship to said arm.

4. The machine of claim 1 wherein said power member is a rectangularmember, and said means slidably capturing said power member is opposeddownwardly depending web members which form said table into a monocoqueconfiguration, the lowermost marginal longitudinally extending edgeportion of said web members being inwardly turned for bottom supportingsaid power member therefrom,

5. The machine of claim 1 wherein said means for reciprocating saidpower member is a hydraulic cylinder, and biasing means are attachedbetween said power member and said table for returning said power memberto a position of rest;

a fixed ear downwardly attached to said table, a pin received throughsaid ear and the cylinder of said hydraulic unit, a movable eardownwardly attached to said power member, a pin received through saidear and the piston of said hydraulic unit,

said biasing means affixed to said pins and biasing them toward oneanother.

6. In a machine for bending a bendable member such as rods, bars, tubes,u-bolts, and the like, the combination comprising a stationary platemember having a longitudinally disposed slot formed therein, a mandrelreceived through said slot and movable longitudinally along the lengththereof, a bending die affixed to said mandrel and movable therewith;

a power member underlying said plate member,

means moving said power member along the length of said slot, saidmandrel being affixed to said power member and movable therewith;

a pair of spaced arms located on either side of the slot, each said armis pivotally secured to said plate member, means forming a fixed die atone end of each arm, means by which said fixed dies may be moved towardone another, said fixed dies being arranged respective to said bendingdie so that the latter is moved through the former by the action of saidpower member;

so that the bendable member can be placed with the fixed and bendingdies arranged on opposite sides thereof, the power member moved alongthe slot, thereby causing the dies to engage and deform the bendablemember into a bent configuration.

7. The combination of claim 6, wherein said mandrel is removably affixedto said power member; and, said bending die is removably affixed to saidmandrel; said bending die having a flat leading edge portion bounded oneither side thereof by a curved trailing surface, with the curvedtrailing surface having a radius of curvature substantially equal to theradius of curvature desired of the bent member. a 8. The combination ofclaim 6 wherein said bending die is a cylindrical member except for theleading edge portion thereof which is made into a flat surface forinitially contacting the bendable member.

9. The combination of claim 6 wherein said bending die has a cylindricalgeometrical configuration with the leading edge portion thereof beingflat so that the flat leading edge portion first contacts the bendablemember and thereafter the spaced curved portion of the cylinder contactsthe bendable member.

10. The combination of claim 6 wherein said power member is an elongatedsquare piece of metal stock, means slidably capturing said power memberin underlying abutting relationship respective to the lower surface ofsaid plate member;

said means for moving said power member being a hydraulic cylinderinterposed between the plate member and the power member;

and further including means for controlling the action of said hydrauliccylinder so that the poiston thereof reciprocates in either of its twodirections of movement.

1. In a bending machine for bending metal stock to produce Ubolts andthe like, a longitudinally extending table having a longitudinallyextending slot formed therein; an elongated slidable power memberunderlying said slot, means slidably capturing said power member to saidtable in a slidable and abutting manner to slidably engage abutingsurfaces of said power member and said table; a mandrel attached to saidpower member and having a free marginal end portion extending throughsaid slot; a movable die affixed to the marginal free end portion ofsaid mandrel; spaced fixed dies equally spaced apart and from saidmovable die; spaced arms pivotally secured to said table and having aswingable end to which there is attached said fixed die; means forreciprocating said power member to move said mandrel along said slot tocause said movable die to move between said fixed dies; so that thecentral marginal length of a piece of metal stock placed against saidfixed dies can be engaged by said movable die and bent into a curvedconfiguration.
 2. The machine of claim 1 wherein said pivoted end ofsaid spaced arms are adjustably secured to one another by a tie rod;means for adjusting the effective length of said tie rod, therebyenabling selection of the distance between said fixed dies.
 3. Themachine of claim 2 wherein said fixed dies include means rotatablysecuring them in fixed relationship to said arm.
 4. The machine of claim1 wherein said power member is a rectangular member, and said meansslidably capturing said power member is opposed downwardly depending webmembers which form said table into a monocoque configuration, thelowermost marginal longitudinally extending edge portion of said webmembers being inwardly turned for bottom supporting said power membertherefrom.
 5. The machine of claim 1 wherein said means forreciprocating said power member is a hydraulic cylinder, and biasingmeans are attached between said power member and said table forreturning said power member to a position of rest; a fixed eardownwardly attached to said table, a pin received through said ear andthe cylinder of said hydraulic unit, a movable ear downwardly attachedto said power member, a pin received through said ear and the piston ofsaid hydraulic unit, said biasing means affixed to said pins and biasingthem toward one another.
 6. In a machine for bending a bendable membersuch as rods, bars, tubes, u-bolts, and the like, the combinationcomprising a stationary plate member having a longitudinally disposedslot formed therein, a mandrel received through said slot and movablelongitudinally along the length thereof, a bending die affixed to saidmandrel and movable therewith; a power member underlying said platemember, means moving said power member along the length of said slot,said mandrel being affixed to said power member and movable therewith; apair of spaced arms located on either side of the slot, each said arm ispivotally secured to said plate member, means forming a fixed die at oneend of each arm, means by which said fixed dies may be moved toward oneanother, said fixed dies being arranged respective to said bending dieso that the latter is moved through the former by the action of saidpower member; So that the bendable member can be placed with the fixedand bending dies arranged on opposite sides thereof, the power membermoved along the slot, thereby causing the dies to engage and deform thebendable member into a bent configuration.
 7. The combination of claim6, wherein said mandrel is removably affixed to said power member; and,said bending die is removably affixed to said mandrel; said bending diehaving a flat leading edge portion bounded on either side thereof by acurved trailing surface, with the curved trailing surface having aradius of curvature substantially equal to the radius of curvaturedesired of the bent member.
 8. The combination of claim 6 wherein saidbending die is a cylindrical member except for the leading edge portionthereof which is made into a flat surface for initially contacting thebendable member.
 9. The combination of claim 6 wherein said bending diehas a cylindrical geometrical configuration with the leading edgeportion thereof being flat so that the flat leading edge portion firstcontacts the bendable member and thereafter the spaced curved portion ofthe cylinder contacts the bendable member.
 10. The combination of claim6 wherein said power member is an elongated square piece of metal stock,means slidably capturing said power member in underlying abuttingrelationship respective to the lower surface of said plate member; saidmeans for moving said power member being a hydraulic cylinder interposedbetween the plate member and the power member; and further includingmeans for controlling the action of said hydraulic cylinder so that thepoiston thereof reciprocates in either of its two directions ofmovement.